Depreciation by Units-of-activity Method A diesel powered tractor with a cost of $392,200 and an estimated residual value of $3,400 is expected to have a useful operating life of 90,000 hours. During Aprit, the tractor was operated 100 hours. Determine the depreciation for the month. If required, carry out any division to two decimal places 4.3 X back Check My We Units-of-activity method allocates the cost of the asset equally over the hours operated the depreciation rate stay contant